Spark plug connection



Feb. 13, 1940. J, M L HAM 2,190,162

SPARK PLUG CONNECTION Filed May 25, 1958 INVENTOR. Jo/m /7. Old/7 am ATTORNEYS PatentedFeb.13,19 40 r 2,190,162

j UNITED stares MM SPARK PLUG CONNECTION 3 John M. Oldham, Pleasantklidge, Mich, assignor to L. A. Young, Detroit, Mich.

Application May 25, 1938, Serial No. 209,905

2 Claims. (01. 173269) This invention relates to a spark plug connec- To form the connection between the cap ll tion and has particularly to do with a device for and the wire, I have provided a closely wound forming a connection between wires from a discoil IT. The lower portion [8 of the coil, as shown tributor of an internal combustion engine and. on the drawing, is adapted to telescope over the the spark plugs of said engine. cap II and to be firmly held thereon. I prefer- Many attempts have been made to provide a ably form the lower portion of this coil with an less expensive spark plug connection than is internal dimension slightly smaller than the exnow generally used. The main difiiculty has been ternal dimensions of the cap I I. The lower porto achieve a device which would stand up against tion of the coil is also provided with an annular 10 the constant vibration to which these parts are concavity on its internal surface to correspond 10 subjected and stillmaintain a proper contact. with the annular convexity l2 on the cap II. By An object of the present invention is to proreason of this formation of the two parts, the vide an inexpensive means for providing a spark coil l2 will be firmly held onthe cap H thereof. plug contact which will not break down under It may be slipped on or pulled off of the cap H constant vibration or under the rough usage to with comparative ease due to the fact that the 15 whichit is subjected by mechanics, etc. coil spring will expand. M

A further object is to provide a spark plug Theupper portion 19 of the coil I1 is adapted connection which may be easily connected and to receive the terminal end of the lead wire l3 disconnected innumerable times without afiectincluding the insulation. The upper portion l9 ing the efliciency of the contacts. of. the coil is also provided with a slightly smaller 20 A- further object is to provide a spark plug internal diameter than the external diameter of 7 connection which needs no soldered or welded the insulation in order to pr vi a Snug fit When joint with the lead wire and which will bend the coil is slipped over the end of the insulated resiliently without being injured. I wire. The coil I! is preferably formed of a spring Other objects and features of the invention steel which is coated with zincplating or copper 5 r having to do with details of construction thereof, plating to carry the electric urrent a bzprewill be further brought out in the following specivent rusting. steel is not an excellent electrical fication and claims. conductor as are zinc, silver and copper. I have In the drawing: i found that plating the coil with one of these Fig. l is a side view of the connection showing better conducting metals makes it an excellent the spark plug and lead wire. conductor for the spark plug connection;

Fig. 2 is a section taken on the lines 22 of The upper end 29 of the wire which forms the Fig. 1. coil is bent diametrically of the coil and pressed Fig. 3 is a side view of the lead wire and c through the rubber insulation l5 to the lead wire n'ecting coil. l3. When the end of the wire 2!] is cut off, it is Figs. 4,5 and 6 are transverse sections taken usually formed i a s p p and this P on the lines 8-4, 5-5 and 6-6, respectively, of will be forced through the strands of the lead Fig. 1. I wire l 3. A positive contactis thus assured be- Fig. 7 illustrates the coil connection in a flexed tween the partsi In view of the fact that a relatively high voltposition. i 40 Referring to the drawing, a spark plug 19 is age passes through the. lead w1re to the spark Shown in Fig 1 A Substantially cylindrical plug, it is unnecessary to solder the connection metal cap H is shown i t top of the Spark between the wire it and the end 20. Even though plug "1 s cap being provided with an annular a gap is left in this contact, it will operate sucbulged or rounded portion cessfully. The rubber 15 will close tightly around 45 A m wire I3 i tta t one end to the end 2B to seal the contact between the end tributor (not shown), and is arranged to be 2|] and the Wire 13 r moistureattached at the other end to the spark plug Hi. I claim: i i

This wire i preferably formed of a number of 1. An electrical connection for, use on a spark copper strands and is insulated with a relatively p u for an, internal combus o e g p 50 heavy insulation l4. The insulation is prefering a cap having a substantially cylindrical shape ably formed of a substantial thickness of rubber with an annular convexity at one portion there- !5 around the wire I3 with a fabric or other of, a lead wire to be connected to said plug, insutype of covering 16. The rubber I5 is preferred lation on said lead wire, and a coil of spring soft and pliable. wire for electrically and physically connecting 55 said cap and said lead wire, one end of said coil being dimensioned to slip over said cap and having an annular concavity on its inner surface to receive the convex portion of said cap in locking relation, the other end of said coil being dimensioned to receive the end of said insulated lead wire, one end of the wire forming said coil being bent diametrically of said coil and driven into'said insulation to contact said lead wire, said end being retained in said position by the resilience of said coil.

2. An electrical connection for use on a spark plug for an internal combustion engine comprising a cap member having an annular restricted 5 portion therein, a lead wire to be connected to said plug, insulation on said lead wire, and a coil of spring wire for electrically and physically connecting said cap member and said lead wire, one end of said coil being dimensioned slightly smaller than said cap member whereby when said end is slipped over said cap, certain winds in said coil will be received by said restricted portion to provide a resilient, yet locked, connection with said cap, the other end of said coil being adapted to receive and retain insulation surrounding said lead wire and having an end portion bent diametrically of said coil and pressed into said insulation to contact said lead wire.

JOHN M. OLDHAM. 

